Sportsman 200

[sportscarpat]

I figured out an intake manifold tonight. Two actually. I like the second one better.


Sportsman 200 by Sportsman Flyer, on Flickr

I used 1" stainless fittings and two different laser cut flanges. I left the manifold in as welded condition so it has a cool gold color going on with a blue and purple color closer to the welds.


Sportsman 200 by Sportsman Flyer, on Flickr

Now I need to figure out the exhaust.


Sportsman 200 by Sportsman Flyer, on Flickr

 

[silverbear]

Lookin' real good, Pat.
SB

 

[whitey]

Pat, stop making me drool. I am getting too impatient with my build and want it to be finished already. Please tell me you will be making a small production run of that manifold

 

[cobrafreak]

Looks clean Pat. If you run a support from the upper right engine mounting bolt to one of the carburetor mounting bolts it makes a good support to keep the manifold from taking the brunt the leverage and it will prevent cracks. The engine is going to vibrate with zest! But you knew this

 

[Waspswatter]

VERY nice Pat,
As for the exhaust: I've considered a fairly large diameter "straight pipe" similar to the early BTR's, with maybe a baffle welded just inside the end (not visible due to the location), then I'd roll up some metal screen and push it through the center hole in the baffle and let it "unroll" befind the baffle. Or maybe you could weld up a baffle assemly to go inside the end of the exhaust pipe. I'm sure you'll think of something

 

[Tre_in_L.A.]

Pat, What an awesome looking machine!

That Bully clutch is a very good part and looks just right too. The engine looks fine and fits into the frame great. Love your intake manifold. The flywheel sets everything off.

Great looking build!

So, when do we head out to the salt? - Bonneville, that is . . .

 

[sportscarpat]

Pat, What an awesome looking machine!

So, when do we head out to the salt? - Bonneville, that is . . .

Bonneville? Sounds like a great idea to me! The pictures alone would be worth the trip. A couple motor bikes with salt crusted tires would be very cool. I tried to make the intake manifold strong enough to take the abuse without adding an extra mount. Right now it makes a good handle for lifting the bike up onto the build stand! It is an overhung load, though, and will be subjected to vibration as well. I'll have to think about adding another mount.

 

[sportscarpat]

I can't wait to see what you do with the exhaust and intake.

When tomgndallas mentioned this my first thought was yeah, I have two more chances to screw up the looks of my build! The Intake manifold luckily looks good enough, so now the exhaust. I was thinking a shorty pipe like on the original boardies, loud as heck and spitting out flames, but I do have to keep the in the neighborhood. I better make something more conservative. I have more fittings so something constructed along the lines of the intake manifold, will be the easy solution. Maybe 1" tubing then bumping up to 2" towards the end. Maybe I need two exhaust pipes, one for racing and youtube videos, and a longer quiet one for the street.

 

[paucmarc]

Having two pipes is a good idea. For the short one maybe something like on the 1909 R-S. Only a longer pipe that ends down towards the bottom of the loop with a bologna cut.

 

[sportscarpat]

Just started working on my "street" exhaust system. Race pipe will come later. Nothing worse than running out of materials when your on a roll! I tried to keep the system tucked in to the engine and use the tubing to act as a bit of a chain/clutch guard.


Sportsman 200 by Sportsman Flyer, on Flickr


Sportsman 200 by Sportsman Flyer, on Flickr

That last 45 degree fitting will continue through to the other side of the frame where I will mount the muffler parallel with the right frame chain stay tube.


Sportsman 200 by Sportsman Flyer, on Flickr

 

[brett7777]

as always, too cool, beautiful work Pat.
hey I saw on the other thread that you're planning to do the frame nickel plated, wow, sweet idea!

 

[Lurker]

Pat,
I was looking at your countershaft to get some ideas for mine because I will not be using a cvt. So I decided to run your gear ratios through this calculator I found and it appears you will only have a top speed of 23 mph. Is this right or am I missing something.

I did the conversion on some of the old btrs and street bikes.
racers: apx.1.95:1 which would yield 80mph.

street models: 4.3:1 @50mph to 3.19:1 @65mph
it should be noted those numbers are for 7-9hp bikes

I will be going with a 2.8:1 with a 23hp engine which should get me to about 80mph and still have enough low end as well. I am sure you have already thought through all of this but I though others might be interested in some of the gear ratios of the original bikes. Since these clone engines are taking over and it would be nice to see some that are not cvt driven like the originals.

 

[sportscarpat]

Hi Lurker,
Interesting. I was not sure what gear ratio to set my system up for, and it is easily changed if I do not get the expected mid range RPM I am after. I followed the advice from AGK and set a final drive ratio of 12.66 to 1. I am also not sure what to expect for max engine rpm, either. Currently I have a 12t/38t primary and a 13t/52t secondary as I recall. I would need to drop down the rear sprocket or make the primary 38t smaller. I guess the question I now have is what is an expected rpm from these engines? I just ran the numbers of my current set-up at 37 mph at 6,000 rpm and 50 mph at 8000 rpm.

 

[sportscarpat]

Lurker,
I just checked the cam and can expect around 8,000 rpm. I have a split 44t rear I can try as well which would put me at 45 mph at 6000 rpm. Actually, I have a whole bunch of ratios I can mess with. This is going to be interesting. What I have found with my Morini build and it's centrifugal clutch is that it's best to spin it up quick so it locks up. Tall gears are hard on clutches.

 

[cobrafreak]

I concur with the 6000 rpm top running speed with the gov removed. Actual redline is 6500 but you don't want to run it so close to the edge. All these industrial engines are governed around 3500rpms and if run it faster you risk severe engine damage if you don't put performance rods in it. HP will mean nothing if you throw a connecting rod through the case.

 

[sportscarpat]

Well, I can always throw a knobbie tire on the rear and call it a hill climber. On my Morini bike I run a 52t around town and bumped down to a 48t on the Whizz-in 90 mile a couple weeks ago. Maybe I'll start with the 52t and bump down to a 44t till I get the feel for things.

John,
How much oil are you running in the Indian? I know you already told me but I forget. I should be firing my motorcycle, I mean BICYCLE, up pretty soon and need to know how much oil to run. I also need to figure out some sort of breather for the valve cover. Lurker, Cobrafreak, CCC, what's the scoop guys? I'd go check your build threads but they are like 20 plus pages long!

 

[cobrafreak]

3/4 of a qt Pat

 

[brett7777]

rpm, teeth, ratios...heck you guys are real gearheads.
80mph on a bicycle !!! maybe you're crazy too ?

 

[cobrafreak]

Rookie level board track racing was around 80mph. Pro level was about 100mph. Oh, you needed pro level guts too, lol.

 

[brett7777]

What speeds are people racing the replicas at your US events, is it called the Grange?